This invention relates to a record cleaner and, more particularly, to a compact disc cleaner that provides good mechanical cleaning of a compact disc.
The recent introduction of the so-called compact disc has resulted in a marked improvement in the quality of reproduced sound, such as music, from what broadly may be called a phonograph record. A conventional compact disc is provided with a surface having "pits" and "lands" arranged in concentric circular tracks, these pits and lands representing digital information that, in turn, constitutes a digitized version of sound. Digital signals are reproduced from the compact disc by scanning its surface with a suitable source of light, typically, a laser beam.
Briefly, the scanning light beam (e.g. the laser) is focused just below the surface of the disc which, typically, is polished and may be, for example, aluminum. The laser beam is reflected from the surface of the disc and is modulated by the pits and lands which it scans. The modulated beam is detected; and the digital information represented by such modulation is decoded and converted to sound. By focusing the laser beam just below the surface of the disc, slight imperfections on the surface of the disc, such as scratches, neither cause nor affect the modulations in the reflected beam. Moreover, since no mechanical elements are brought into contact with the surface of the disc, the disc is not subjected to wear and, in theory, there is no practical limit on the number of times that disc may be replayed. This contrasts with typical contemporary phonograph systems in which a phonograph needle rides in a spiral groove of the phonograph disc resulting in wear on both the groove and the needle, as well as wear on the pick-up cartridge that is used with that needle, thereby limiting the longevity of the phonograph disc and pick-up transducer.
Notwithstanding the generally good resistance of the optically readable compact disc to sound distortion caused by imperfections in the surface of the disc, as aforementioned, perturbations may be imparted to the scanning laser beam, resulting in sound distortion, due to fingerprints, oil and soil adhering to the surface of the disc. Accordingly, it is a recognized objective to provide some form of cleaning apparatus by which the surface of the compact disc may be wiped to remove or at least reduce the aforementioned impairments from the disc. However, in view of the sensitivity of the disc to potential damage, devices that have been used heretofore in the cleaning of phonograph records cannot be used to clean compact discs. One proposal to clean the surface of the compact disc requires a user to manually wipe the surface of the disc with a hand-held cleaning pad subsequent to the application to that surface of a suitable cleaning spray. This cleaner is available from Nagaoka & Company from Japan.
However, such manual cleaning apparatus is less than perfect. Notwithstanding cautionary instructions that are provided therewith, it is expected that different users will manipulate the cleaning pad in different fashions, resulting in varied results, including the possibility of seriously damaging the compact disc. Also, although the manual cleaning of a compact disc does not appear to be an arduous task, it is expected that, in the absence of some automatic cleaning device, several users will wish not to be bothered with manual cleaning.